1. Technical Field
The present invention relates to a turbo compressor capable of compressing fluid by its plural impeller.
2. Background Art
As a conventional turbo compressor to be applied to a turbo refrigerator or the like, one disclosed in a Patent Document 1 (Japanese Patent Application Laid-Open No. 2011-26960) is known. The turbo compressor includes a housing in which lubrication oil is accumulated, a large-diameter gear housed in the housing, and a demister disposed above the large-diameter gear in the housing. The large-diameter gear supplies the lubrication oil by its rotations. The demister is provided with intakes communicating with an outside of the housing. The demister catches oil mist of the lubrication oil splashed by rotations of the large-diameter gear to return it to a lower portion of the housing.
In the turbo compressor, the intakes of the demister are connected with a lower-pressure space than an inside of the housing via a pressure equalizing pipe, and thereby pressure rise in the housing is restricted. In addition, the oil mist of the lubrication oil is generated in the housing by the rotations of the large-diameter gear. Therefore, the demister catches the oil mist when inside air in the housing is inhaled from the intakes and returns it to the lower portion of the housing in order to prevent the lubrication oil from being discharged out from the housing.